Heat exchanger and refrigeration cycle apparatus

ABSTRACT

A heat exchanger includes a first heat exchange portion and a second heat exchange portion. The first heat exchange portion includes a plurality of first flat tubes. The second heat exchange portion includes a plurality of second flat tubes. The heat exchanger further includes: a first header; a second header; and a third header connected to each of the first flat tubes and each of the second flat tubes. The third header includes: a first plate provided with a plurality of first insertion holes through which the second ends of the first flat tubes are respectively inserted and a plurality of second insertion holes through which the second ends of the second flat tubes are respectively inserted; and a second plate provided with a plurality of communication spaces each communicating with a corresponding one of the first insertion holes and a corresponding one of the second insertion holes.

CROSS REFERENCE TO RELATED APPLICATION

This application is a U.S. national stage application of InternationalPatent Application No. PCT/JP2020/039355 filed on Oct. 20, 2020, thedisclosure of which is incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a heat exchanger and a refrigerationcycle apparatus.

BACKGROUND

Japanese Patent Laying-Open No. 2015-113983 discloses a heat exchangerincluding: a first heat exchange element having a plurality of firstflat tubes; a second heat exchange element having a plurality of secondflat tubes; and a folded header at which refrigerant having passedthrough the first heat exchange element is turned and introduced intothe second heat exchange element.

PATENT LITERATURE

PTL 1: Japanese Patent Laying-Open No. 2015-113983

In the above-mentioned heat exchanger, since each of the first flattubes and each of the second flat tubes are disposed at the same heightin the vertical direction, one of each first flat tube and each secondflat tube is located downstream of the other in the ventilationdirection. In other words, in the ventilation direction, the flat tubesdisposed on the downstream side are located in the dead water zoneformed behind the flat tubes disposed on the upstream side. As a result,in the above-mentioned heat exchanger, the heat exchange performance ofthe heat exchange element disposed downstream in the ventilationdirection cannot be sufficiently exhibited.

SUMMARY

A main object of the present disclosure is to provide a heat exchangerenhanced in heat exchange performance as compared with theabove-mentioned conventional heat exchanger, and a refrigeration cycleapparatus including the heat exchanger.

A heat exchanger according to a first aspect of the present disclosureincludes: a first heat exchange portion and a second heat exchangeportion arranged side by side in a first direction intersecting with adirection of gravity. The first heat exchange portion has: a pluralityof first fins extending in the direction of gravity and arranged side byside in a second direction intersecting with the direction of gravityand the first direction; and a plurality of first flat tubes mounted tointersect with each of the first fins and arranged side by side in thedirection of gravity. The second heat exchange portion has: a pluralityof second fins extending in the direction of gravity and arranged sideby side in the second direction; and a plurality of second flat tubesmounted to intersect with each of the second fins and arranged side byside in the direction of gravity. The heat exchanger further includes: afirst header connected to a first end of each of the first flat tubes; asecond header connected to a first end of each of the second flat tubes;and a third header connected to a second end of each of the first flattubes and a second end of each of the second flat tubes. When viewed inthe first direction, each of the second flat tubes is disposed not tooverlap with each of the first flat tubes. The third header has: a firstplate provided with a plurality of first insertion holes through whichthe second ends of the first flat tubes are respectively inserted, and aplurality of second insertion holes through which the second ends of thesecond flat tubes are respectively inserted; and a second plate providedwith a plurality of communication spaces each communicating with acorresponding one of the first insertion holes and a corresponding oneof the second insertion holes.

A heat exchanger according to a second aspect of the present disclosureincludes a first heat exchange portion and a second heat exchangeportion arranged side by side in a first direction intersecting with adirection of gravity. The first heat exchange portion has: a pluralityof first fins extending in the direction of gravity and arranged side byside in a second direction intersecting with the direction of gravityand the first direction; and a plurality of first flat tubes mounted tointersect with each of the first fins and arranged side by side in thedirection of gravity. The second heat exchange portion has: a pluralityof second fins extending in the direction of gravity and arranged sideby side in the second direction; and a plurality of second flat tubesmounted to intersect with each of the second fins and arranged side byside in the direction of gravity. The heat exchanger further includes: afirst header connected to a first end of each of the first flat tubes; asecond header connected to a first end of each of the second flat tubes;and a third header connected to a second end of each of the first flattubes and a second end of each of the second flat tubes, the thirdheader being provided with a plurality of communication spaces eachcommunicating with a corresponding one of the first flat tubes and acorresponding one of the second flat tubes. When viewed in the firstdirection, each of the second flat tubes is disposed not to overlap witheach of the first flat tubes. At least one of the first flat tubes thatis connected to one communication space of the communication spaces islocated lower in the direction of gravity than at least one of thesecond flat tubes that is connected to the one communication space.

The present disclosure can provide a heat exchanger improved in heatexchange performance as compared with the above-mentioned conventionalheat exchanger, and a refrigeration cycle apparatus including the heatexchanger.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a top view of a heat exchanger according to a firstembodiment.

FIG. 2 is a front view of the heat exchanger shown in FIG. 1 .

FIG. 3 is a side view of the heat exchanger shown in FIG. 1 .

FIG. 4 is a partial cross-sectional view for illustrating configurationsof a first fin, a first flat tube, a second fin, and a second flat tubein the heat exchanger shown in FIG. 1 .

FIG. 5 is a diagram for illustrating a first plate of a bridging headershown in FIG. 1 .

FIG. 6 is a diagram for illustrating a second plate of the bridgingheader shown in FIG. 1 .

FIG. 7 is a diagram for illustrating a third plate of the bridgingheader shown in FIG. 1 .

FIG. 8 is an exploded perspective view for illustrating a connectionrelation among the first plate, the second plate, and the third plate ofthe bridging header shown in FIG. 1 .

FIG. 9 is a partial cross-sectional view taken along a line indicated byan arrow IX-IX in FIG. 1 .

FIG. 10 is a partial cross-sectional view showing a modification of thefirst plate, the second plate, and the third plate shown in FIG. 9 .

FIG. 11 is a partial cross-sectional view for illustratingconfigurations of a first fin, a first flat tube, a second fin, and asecond flat tube in a heat exchanger according to a second embodiment.

FIG. 12 is a diagram for illustrating a first plate of a bridging headerin the heat exchanger according to the second embodiment.

FIG. 13 is a diagram for illustrating a second plate of the heatexchanger according to the second embodiment.

FIG. 14 is a top view of a heat exchanger according to a thirdembodiment.

FIG. 15 is a front view of the heat exchanger shown in FIG. 14 .

FIG. 16 is a side view of the heat exchanger shown in FIG. 14 .

FIG. 17 is a diagram for illustrating a first plate of a bridging headershown in FIG. 14 .

FIG. 18 is a diagram for illustrating a second plate of the bridgingheader shown in FIG. 14 .

FIG. 19 is a diagram for illustrating a third plate of the bridgingheader shown in FIG. 14 .

DETAILED DESCRIPTION

The following describes embodiments as examples of a heat exchangeraccording to the present disclosure with reference to the accompanyingdrawings. In the accompanying drawings, the same or correspondingportions are denoted by the same reference characters, and thedescription thereof will not be repeated. Further, in each of thefigures, for convenience of explanation, an X direction, a Y direction,and a Z direction orthogonal to each other are introduced. The Xdirection and the Y direction corresponds to the horizontal directionwhile the Z direction corresponds to the direction of gravity.

First Embodiment

As shown in FIGS. 1 to 3 , a heat exchanger 100 according to the firstembodiment includes a first heat exchange portion 11, a second heatexchange portion 12, a first header 13, a second header 14, and a thirdheader (hereinafter, referred to as a bridging header) 15.

As shown in FIGS. 1, 2, and 4 , each of first heat exchange portion 11and second heat exchange portion 12 is provided so as to exchange heatbetween the refrigerant flowing in the X direction (the seconddirection) and air flowing in the Y direction. First heat exchangeportion 11 and second heat exchange portion 12 are arranged side by sidein the Y direction (the first direction). In the following description,in the Y direction, the upstream side in the ventilation direction willbe simply referred to as a windward side while the downstream side inthe ventilation direction will be simply referred to as a leeward side.First heat exchanging portion 11 is disposed on the windward siderelative to second heat exchanging portion 12.

As shown in FIGS. 1, 2, and 4 , first heat exchange portion 11 includesa plurality of first fins 1 and a plurality of first flat tubes 2. Theplurality of first fins 1 extend in the Z direction and the Y direction,and are arranged side by side in the X direction. Each of first fins 1is a plate fin. The plurality of first flat tubes 2 are mounted tointersect with each of the plurality of first fins 1, and are arrangedside by side in the Z direction. The cross-sectional shape of each firstflat tube 2 perpendicular to the X direction is a flat shape having along-side direction and a short-side direction. The long-side directionof each first flat tube 2 corresponds to the Y direction. In first heatexchange portion 11, heat is exchanged between: air flowing in the Ydirection between first fins 1 adjacent to each other; and therefrigerant flowing in the X direction through each first flat tube 2. Aplurality of flow paths are formed inside each first flat tube 2. Theflow paths each extend in the axial direction (the X direction) of eachfirst flat tube 2 and are arranged side by side in the long-sidedirection of each first flat tube 2.

As shown in FIGS. 1, 2, and 4 , second heat exchange portion 12 includesa plurality of second fins 3 and a plurality of second flat tubes 4. Theplurality of second fins 3 extend in the Z direction and the Ydirection, and are arranged side by side in the X direction. Each secondfin 3 is a plate fin. The plurality of second flat tubes 4 are mountedto intersect with each of the plurality of second fins 3 and arearranged side by side in the Z direction. The cross-sectional shape ofeach second flat tube 4 perpendicular to the X direction is a flat shapehaving a long-side direction and a short-side direction. In second heatexchange portion 12, heat is exchanged between: air flowing in the Ydirection between second fins 3 adjacent to each other; and therefrigerant flowing in the X direction through each second flat tube 4.A plurality of flow paths are formed inside each second flat tube 4. Theflow paths each extend in the axial direction (the X direction) of eachsecond flat tube 4 and are arranged side by side in the long-sidedirection of each second flat tube 4.

As shown in FIGS. 1 and 4 , each second fin 3 is spaced apart in the Ydirection from each first fin 1. Each second fin 3 is disposed on theleeward side relative to each first fin 1. An end portion 3A located onthe windward side of each second fin 3 is disposed on the leeward siderelative to an end portion 1B located on the leeward side of each firstfin 1.

As shown in FIGS. 1 and 4 , each second flat tube 4 is spaced apart inthe Y direction from each first flat tube 2. Each second flat tube 4 isdisposed on the leeward side relative to each first flat tube 2. An endportion located on the windward side of each second flat tube 4 isdisposed on the leeward side relative to an end portion located on theleeward side of each first flat tube 2.

As shown in FIG. 2 , each second fin 3 is disposed to overlap with eachfirst fin 1 when viewed in the Y direction. Each second fin 3 is formedas a member separate from each first fin 1.

As shown in FIGS. 2 and 4 , each second flat tube 4 is disposed not tooverlap with each first flat tube 2 when viewed in the Y direction. Whenviewed in the Y direction, each first flat tube 2 is disposed betweentwo second flat tubes 4 adjacent to each other in the Z direction. Whenviewed in the Y direction, each second flat tube 4 is disposed betweentwo first flat tubes 2 adjacent to each other in the Z direction.

As shown in FIG. 4 , each first fin 1 has a continuous portion 1Ddisposed on one side (for example, on the windward side) in the Ydirection and extending in the Z direction. Each first fin 1 is providedwith a plurality of insertion holes 1C disposed on the other side (forexample, on the leeward side) in the Y direction with respect tocontinuous portion 1D. Through each insertion hole 1C, each first flattube 2 is inserted. Continuous portion 1D is located between an endportion 1A located on the windward side of first fin 1 and an endportion located on the windward side of each insertion hole 1C. Eachinsertion hole 1C is opened, for example, at end portion 1B located onthe leeward side of first fin 1. Note that each insertion hole 1C maynot be opened at end portion 1B located on the leeward side of first fin1.

As shown in FIG. 4 , each second fin 3 has a continuous portion 3Ddisposed on one side (for example, on the windward side) in the Ydirection and extending in the Z direction. Each second fin 3 isprovided with a plurality of insertion holes 3C disposed on the otherside (for example, on the leeward side) in the Y direction with respectto continuous portion 3D. Through each insertion hole 3C, each secondflat tube 4 is inserted. Continuous portion 3D is located between endportion 3A located on the windward side of second fin 3 and the endportion located on the windward side of each insertion hole 3C. Eachinsertion hole 3C is opened, for example, at an end portion 3B locatedon the leeward side of second fin 3. Each insertion hole 3C may not beopened at end portion 3B located on the leeward side of second fin 3.

As shown in FIGS. 1 and 2 , first header 13 is connected to a first endof each first flat tube 2 in the Y direction. First header 13 allowsmerging of the refrigerant having flowed out of each first flat tube 2or allows splitting of the refrigerant that is to flow into each firstflat tube 2. Second header 14 is connected to the first end of eachsecond flat tube 4 in the Y direction, and allows merging of therefrigerant having flowed out of each second flat tube 4 or allowssplitting of the refrigerant that is to flow into each second flat tube4. Second header 14 is disposed on the leeward side relative to firstheader 13.

As shown in FIGS. 1 to 3 , bridging header 15 is connected to the secondend of each first flat tube 2 and the second end of each second flattube 4. Bridging header 15 provides communication between each firstflat tube 2 and each second flat tube 4 for refrigerant to flowtherebetween.

As shown in FIG. 3 , bridging header 15 is provided with: a plurality offirst insertion holes 16 through which first flat tubes 2 arerespectively inserted; a plurality of second insertion holes 17 throughwhich second flat tubes 4 are respectively inserted; and a plurality ofcommunication spaces 18 each communicating with a corresponding one offirst insertion holes 16 and a corresponding one of second insertionholes 17. First insertion holes 16 are arranged side by side in the Zdirection. Second insertion holes 17 are arranged side by side in the Zdirection. Each second insertion hole 17 is spaced apart in the Ydirection from each first insertion hole 16. Further, each secondinsertion hole 17 is spaced apart in the Z direction from each firstinsertion hole 16.

As shown in FIGS. 3 and 6 , each communication space 18 is provided toallow communication between one first insertion hole 16 and one secondinsertion hole 17 that is disposed adjacent to this one first insertionhole 16 in the Z direction and located above this one first insertionhole 16. In other words, each communication space 18 providescommunication between one first flat tube 2 and one second flat tube 4that is disposed adjacent to this one first flat tube 2 in the Zdirection and located above this one first flat tube 2, for refrigerantto flow therebetween.

As shown in FIGS. 1 and 2 , bridging header 15 includes a first plate15A, a second plate 15B, and a third plate 15C. First plate 15A, secondplate 15B, and third plate 15C are stacked in the X direction. Firstplate 15A is disposed on the side close to first heat exchange portion11 and second heat exchange portion 12 with respect to second plate 15Band third plate 15C in the X direction. Third plate 15C is disposed onthe side opposite to first heat exchange portion 11 and second heatexchange portion 12 with respect to first plate 15A and second plate 15Bin the X direction. Second plate 15B is sandwiched between first plate15A and third plate 15C in the X direction. First plate 15A, secondplate 15B, and third plate 15C are connected and fixed to each other ina water-tight manner. The materials forming first plate 15A, secondplate 15B, and third plate 15C include aluminum (Al), for example.

As shown in FIGS. 3, 5, and 8 , first plate 15A is provided with aplurality of through holes. The through holes provided in first plate15A constitute first insertion holes 16 or second insertion holes 17. Inother words, first insertion holes 16 and second insertion holes 17 areprovided as through holes in first plate 15A. First insertion holes 16and second insertion holes 17 each may be formed by any method and, forexample, are formed by press working. First plate 15A serves as aconnection plate connected to each first flat tube 2 and each secondflat tube 4 in a water-tight manner.

As shown in FIGS. 3, 6, and 8 , second plate 15B is provided with aplurality of through holes. The inner space of each through holeprovided in second plate 15B provides communication space 18. In otherwords, each communication space 18 is an inner space of each of theplurality of through holes provided in second plate 15B. When viewed inthe X direction, each through hole provided in second plate 15B isprovided to overlap with the entirety of one first insertion hole 16 andone second insertion hole 17. When viewed in the X direction, theopening end of each through hole provided in second plate 15B is locatedoutside each of the opening ends of each first insertion hole 16 andeach second insertion hole 17 provided in first plate 15A. Each throughhole provided in second plate 15B may be formed by any method and, forexample, are formed by press working. Second plate 15B is a flow pathplate providing communication space 18 as a refrigerant flow pathbetween first flat tube 2 and second flat tube 4.

As shown in FIGS. 3 and 6 , one first flat tube 2 connected to onecommunication space 18 is located lower in the Z direction than onesecond flat tube 4 connected to this one communication space 18.Specifically, the uppermost portion of one first flat tube 2 connectedto one communication space 18 is located at the same height in the Zdirection as the lowermost portion of one second flat tube 4 connectedto this one communication space 18, or located lower than the lowermostportion.

The inner circumferential surface of each through hole provided insecond plate 15B has a pair of inclined surfaces facing each other inthe Z direction and inclined with respect to the X direction and the Ydirection. The pair of inclined surfaces is inclined gradually upward tothe leeward side. The distance between the pair of inclined surfaces inthe Z direction is larger than the width of each first insertion hole 16in the Z direction and the width of each second insertion hole 17 in theZ direction.

As shown in FIGS. 3, 7, and 8 , third plate 15C is disposed on the sideopposite to each first insertion hole 16 and each second insertion hole17 with respect to each communication space 18, and closes one end ofeach communication space 18 in the X direction. In third plate 15C, nothrough hole is formed in a region overlapping with communication space18 when viewed in the X direction. Third plate 15C forms what is calledan outer shell plate.

As shown in FIG. 9 , first plate 15A is smaller in thickness than secondplate 15B. Third plate 15C is smaller in thickness than second plate15B. First plate 15A is larger in thickness than third plate 15C, forexample. First flat tube 2 is fixed to first plate 15A, for example, bya brazing material. In this case, after first flat tube 2 is insertedinto first insertion hole 16 and second flat tube 4 is inserted intosecond insertion hole 17, first flat tube 2 and second insertion hole 17are fixed to first plate 15A by a brazing material. Then, second plate15B and third plate 15C are fixed to first plate 15A by a brazingmaterial. In this way, each first flat tube 2, each second flat tube 4,and bridging header 15 are connected and fixed to each other in awater-tight manner.

Functions and Effects

In heat exchanger 100, each of second flat tubes 4 is disposed not tooverlap with each of first flat tubes 2 when viewed in the Y direction.In other words, in heat exchanger 100, each second flat tube 4 disposedon the leeward side is not located in the dead water zone of each firstflat tube 2 disposed on the windward side. Thus, the heat exchangeperformance of heat exchanger 100 is enhanced as compared with the heatexchange performance of the heat exchanger in which each first flat tubeand each second flat tube are disposed at the same height in thevertical direction.

Further, bridging header 15 of heat exchanger 100 includes: first plate15A provided with first insertion holes 16 through which the second endsof first flat tubes 2 are respectively inserted and second insertionholes 17 through which the second ends of second flat tubes 4 arerespectively inserted; and second plate 15B provided with communicationspaces 18 each communicating with a corresponding one of first insertionholes 16 and a corresponding one of second insertion holes 17.

In bridging header 15 as described above, each of first plate 15A andsecond plate 15B formed of separate plate members is provided with:first insertion holes 16 and second insertion holes 17 through whichfirst flat tubes 2 and second flat tubes 4 are respectively inserted;and communication spaces 18 each providing communication between eachfirst flat tube 2 and each second flat tube 4 for refrigerant to flowtherebetween. Thus, the degree of freedom for the shapes of each firstinsertion hole 16, each second insertion hole 17, and each communicationspace 18 in bridging header 15 is enhanced as compared with the degreeof freedom for the shape of the bridging header in which each firstinsertion hole, each second insertion hole, and each communication spaceare formed in one member. As a result, in bridging header 15, even wheneach second flat tube 4 is disposed not to overlap with each first flattube 2 when viewed in the Y direction, the insertion margins for eachfirst insertion hole 16 and each second insertion hole 17 can be readilyensured and the volume of each communication space 18 can be readilyincreased, as compared with the bridging header in which each firstinsertion hole, each second insertion hole, and each communication spaceare provided in one member.

As a result, in heat exchanger 100 including bridging header 15described above, the heat exchange performance can be readily enhancedas compared with the heat exchanger including the bridging header inwhich each first insertion hole, each second insertion hole, and eachcommunication space are provided in one member.

In heat exchanger 100, first plate 15A is smaller in thickness thansecond plate 15B. This makes it possible to simultaneously increase thevolume of each communication space 18 and the insertion margins for eachfirst insertion hole 16 and each second insertion hole 17, as comparedwith the case in which the thickness of first plate 15A is equal to orlarger than the thickness of second plate 15B.

In heat exchanger 100, one first flat tube 2 connected to onecommunication space 18 is located lower in the Z direction than onesecond flat tube 4 connected to this one communication space 18.

In this way, when refrigerant flows from second flat tube 4 to firstflat tube 2 through communication space 18, gravity acts on thisrefrigerant in the flow direction of the refrigerant. In such heatexchanger 100, as compared with the heat exchanger in which each firstflat tube and each second flat tube are disposed at the same height inthe vertical direction, the pressure loss of the gas-liquid two-phaserefrigerant having flowed out of second flat tube 4 is reduced, so thatthe heat exchange performance is enhanced.

Modification

Each communication space 18 only needs to provide communication betweenat least one first flat tube 2 and at least one second flat tube 4 forrefrigerant to flow therebetween. Each communication space 18 may beformed, for example, to provide communication between the plurality offirst flat tubes 2 and the plurality of second flat tubes 4 forrefrigerant to flow therebetween.

Second plate 15B may be provided with a plurality of recesses in placeof the plurality of through holes. In this case, each communicationspace 18 is formed of an inner space of a recess provided in secondplate 15B. Bridging header 15 may not include third plate 15C and may beformed as a multilayer body of first plate 15A and second plate 15B.

As shown in FIG. 10 , a plurality of recesses 15D may be provided in thesurface of third plate 15C on the side close to second plate 15B. Eachof the plurality of recesses 15D is provided to overlap with each of thethrough holes provided in second plate 15B when viewed in the Xdirection. The region of third plate 15C where no recess 15D is providedis formed to overlap with the region of second plate 15B where nothrough hole is provided when viewed in the X direction. In this case,the inner space of each recess 15D provided in third plate 15Ccommunicates with the inner space of each through hole provided insecond plate 15B, and each communication space 18 is formed of theabove-mentioned two inner spaces.

In bridging header 15, second plate 15B may be configured as amultilayer body formed of a plurality of plates. As long as the entirethickness of second plate 15B is larger than the thickness of firstplate 15A, the thickness of each plate forming second plate 15B may beequal to or smaller than the thickness of first plate 15A.

In this way, the pressure resistance of second plate 15B can be enhancedwithout impairing the formability of second plate 15B as compared withthe case in which second plate 15B is formed as one plate.

Further, in bridging header 15, the plurality of first insertion holes16, the plurality of second insertion holes 17, and the plurality ofcommunication spaces 18 may be provided in one member. Bridging header15 as described above may be formed by laser processing, for example.

Second Embodiment

A heat exchanger according to the second embodiment has basically thesame configuration and exhibits basically the same effect as those ofheat exchanger 100 according to the first embodiment, but is differentfrom heat exchanger 100 in that each first flat tube 2 and each secondflat tube 4 have upper surfaces 2A and 4A, respectively, inclined withrespect to the horizontal direction and that each communication space 18extends along upper surfaces 2A and 4A, as shown in FIGS. 11 to 13 .

The angle formed by upper surface 2A with respect to the horizontaldirection is 5 degrees or more and 45 degrees or less, for example. Theangle formed by upper surface 4A with respect to the horizontaldirection is 5 degrees or more and 45 degrees or less, for example. Theangle formed by upper surface 2A of first flat tube 2 with respect tothe horizontal direction is, for example, equal to the angle formed byupper surface 4A of second flat tube 4 with respect to the horizontaldirection. Upper surface 2A of one first flat tube 2 connected to onecommunication space 18 is, for example, disposed to be flush with uppersurface 4A of one second flat tube 4 connected to this one communicationspace 18.

In the heat exchanger according to the second embodiment, each firstflat tube 2 and each second flat tube 4 have upper surfaces 2A and 4A,respectively, inclined with respect to the horizontal direction, andeach communication space 18 extends along upper surfaces 2A and 4A, andthereby, imbalance in distribution of the refrigerant from communicationspace 18 to the flow paths of first flat tubes 2 is suppressed.

Note that modifications similar to those of the heat exchanger accordingto the first embodiment are allowable also in the heat exchangeraccording to the second embodiment.

Third Embodiment

A heat exchanger 101 according to the third embodiment has basically thesame configuration and exhibits basically the same effect as those ofheat exchanger 100 according to the first embodiment, but is differentfrom heat exchanger 100 in that bridging header 15 is divided into aplurality of sections as shown in FIGS. 14 to 16 .

Bridging header 15 is divided into a first bridging header 19 disposedabove in the Z direction and a second bridging header 20 disposed belowin the Z direction. The plurality of first flat tubes 2 are divided intofirst flat tubes 2 of a first group disposed above and first flat tubes2 of a second group disposed below first flat tubes 2 of the firstgroup. The plurality of second flat tubes 4 are divided into second flattubes 4 of a first group disposed above and second flat tubes 4 of asecond group disposed below second flat tubes 4 of the first group.

First bridging header 19 is connected to each of the second ends offirst flat tubes 2 of the first group and each of the second ends ofsecond flat tubes 4 of the first group, and allows merging of therefrigerant having flowed out of each of second flat tubes 4 of thefirst group and also allows splitting of the refrigerant that is to flowinto each of first flat tubes 2 of the first group.

Second bridging header 20 is connected to each of the second ends offirst flat tubes 2 of the second group and each of the second ends ofsecond flat tubes 4 of the second group, and allows merging of therefrigerant having flowed out of each of second flat tubes 4 of thesecond group and also allows splitting of the refrigerant that is toflow into each of first flat tubes 2 of the second group.

First bridging header 19 includes a first plate 19A, a second plate 19B,and a third plate 19C. First plate 19A, second plate 19B, and thirdplate 19C have the same configurations as those of first plate 15A,second plate 15B, and third plate 15C described above.

Second bridging header 20 includes a first plate 20A, a second plate20B, and a third plate 20C. First plate 20A, second plate 20B, and thirdplate 20C have the same configurations as those of first plate 15A,second plate 15B, and third plate 15C described above.

First plates 19A and 20A are configured as plate members different fromeach other, for example. Second plates 19B and 20B are configured asplate members different from each other, for example. Third plates 19Cand 20C are configured as plate members different from each other, forexample. Note that first plates 19A and 20A may be configured as oneplate member. Second plates 19B and 20B may be configured as one platemember. Third plates 19C and 20C may be configured as one plate member,for example.

As shown in FIG. 16 , a plurality of through holes are provided in eachof first plates 19A and 20A. Each through hole provided in each of firstplates 19A and 20A constitutes a first insertion hole 21 or a secondinsertion hole 22. In other words, each first insertion hole 21 and eachsecond insertion hole 22 are provided as a through hole in each of firstplates 19A and 20A.

As shown in FIG. 17 , second plates 19B and 20B each are provided with aplurality of through holes. The inner space of each through holeprovided in each of second plates 19B and 20B provides a communicationspace 23. Each communication space 23 is an inner space of each of theplurality of through holes provided in each of second plates 19B and20B. When viewed in the X direction, each through hole provided in eachof second plates 19B and 20B is formed to overlap with the entirety ofone first insertion hole 21 and one second insertion hole 22. Whenviewed in the X direction, the opening end of each through hole providedin each of second plates 19B and 20B is located outside each of theopening ends of each first insertion hole 21 and each second insertionhole 22 provided in each of first plates 19A and 20A.

As shown in FIGS. 16 and 18 , one first flat tube 2 connected to onecommunication space 23 is located lower in the Z direction than onesecond flat tube 4 connected to this one communication space 23.Specifically, the uppermost portion of one first flat tube 2 connectedto one communication space 18 is disposed at the same height in the Zdirection as the lowermost portion of one second flat tube 4 connectedto this one communication space 18, or located lower than the lowermostportion.

The inner circumferential surface of each through hole provided in eachof second plates 19B and 20B has a pair of inclined surfaces facing eachother in the Z direction and inclined with respect to the X directionand the Y direction. The pair of inclined surfaces is inclined graduallyupward to the leeward side. The distance between the pair of inclinedsurfaces in the Z direction is larger than the width of each firstinsertion hole 21 in the Z direction and the width of each secondinsertion hole 22 in the Z direction.

As shown in FIGS. 15 and 19 , third plates 19C and 20C each are disposedon the side opposite to each first insertion hole 21 and each secondinsertion hole 22 with respect to each communication space 23, and closeone end of each communication space 23 in the X direction. In each ofthird plates 19C and 20C, no through hole is provided in a regionoverlapping with communication space 23 when viewed in the X direction.

Note that modifications similar to those of the heat exchanger accordingto the first embodiment are allowable also in heat exchanger 101according to the third embodiment.

Fourth Embodiment Refrigeration Cycle Apparatus

A refrigeration cycle apparatus 200 according to the fourth embodimentincludes any one of the heat exchangers according to the first to thirdembodiments as an evaporator. Refrigeration cycle apparatus 200 mainlyincludes a compressor 111, heat exchangers 100, 101, a heat exchanger113, and an expansion valve 114. In refrigeration cycle apparatus 200,second header 14 serves as an inflow portion of refrigerant, and firstheader 13 serves as an outflow portion of refrigerant. In each of heatexchangers 100 and 101 serving as evaporators, the refrigerant flowsthrough second header 14, second heat exchange portion 12, bridgingheader 15, first heat exchange portion 11, and first header 13 in thisorder. The gas-liquid two-phase refrigerant that has been condensed inheat exchanger 113 and then decompressed by expansion valve 114 flowsinto second header 14. The gas-liquid two-phase refrigerant exchangesheat with air flowing in the Y direction through second heat exchangeportion 12 and first heat exchange portion 11 and thereby evaporates andturns into gas-phase refrigerant. This gas-phase refrigerant flows outof first header 13 and is suctioned into compressor 111. Note thatrefrigeration cycle apparatus 200 may further include a four-way valve112 for switching the flow direction of the refrigerant. Four-way valve112 switches the operation mode between an operation mode in which heatexchanger 100, 101 serves as an evaporator and an operation mode inwhich heat exchanger 100, 101 serves as a condenser.

Although the embodiments of the present disclosure have been describedas above, the above-described embodiments can also be variouslymodified. Further, the scope of the present disclosure is not limited tothe above-described embodiments. The scope of the present disclosure isdefined by the terms of the claims and is intended to include anymodifications within the meaning and scope equivalent to the terms ofthe claims.

1. A heat exchanger comprising: a first heat exchange portion and asecond heat exchange portion arranged side by side in a first directionintersecting with a direction of gravity, the first heat exchangeportion having a plurality of first fins extending in the direction ofgravity and arranged side by side in a second direction intersectingwith the direction of gravity and the first direction, and a pluralityof first flat tubes mounted to intersect with each of the first fins andarranged side by side in the direction of gravity, the second heatexchange portion having a plurality of second fins extending in thedirection of gravity and arranged side by side in the second direction,and a plurality of second flat tubes mounted to intersect with each ofthe second fins and arranged side by side in the direction of gravity,the heat exchanger further comprising: a first header connected to afirst end of each of the first flat tubes; a second header connected toa first end of each of the second flat tubes; and a third headerconnected to a second end of each of the first flat tubes and a secondend of each of the second flat tubes, wherein when viewed in the firstdirection, each of the second flat tubes is disposed not to overlap witheach of the first flat tubes, and the third header has a first plateprovided with a plurality of first insertion holes through which thesecond ends of the first flat tubes are respectively inserted, and aplurality of second insertion holes through which the second ends of thesecond flat tubes are respectively inserted, and a second plate providedwith a plurality of communication spaces each communicating with acorresponding one of the first insertion holes and a corresponding oneof the second insertion holes, and a third plate disposed on the sideopposite to each of the first insertion hole and each of the secondinsertion hole with respect to each of the communication space, andclosing one end of each of the communication space in the seconddirection.
 2. The heat exchanger according to claim 1, wherein at leastone of the first flat tubes that is connected to one communication spaceof the communication spaces is located lower in the direction of gravitythan at least one of the second flat tubes that is connected to the onecommunication space.
 3. A heat exchanger comprising: a first heatexchange portion and a second heat exchange portion arranged side byside in a first direction intersecting with a direction of gravity, thefirst heat exchange portion having a plurality of first fins extendingin the direction of gravity and arranged side by side in a seconddirection intersecting with the direction of gravity and the firstdirection, and a plurality of first flat tubes mounted to intersect witheach of the first fins and arranged side by side in the direction ofgravity, the second heat exchange portion having a plurality of secondfins extending in the direction of gravity and arranged side by side inthe second direction, and a plurality of second flat tubes mounted tointersect with each of the second fins and arranged side by side in thedirection of gravity, the heat exchanger further comprising: a firstheader connected to a first end of each of the first flat tubes; asecond header connected to a first end of each of the second flat tubes;and a third header connected to a second end of each of the first flattubes and a second end of each of the second flat tubes, the thirdheader being provided with a plurality of communication spaces eachcommunicating with a corresponding one of the first flat tubes and acorresponding one of the second flat tubes, wherein when viewed in thefirst direction, each of the second flat tubes is disposed not tooverlap with each of the first flat tubes, and at least one of the firstflat tubes that is connected to one communication space of thecommunication spaces is located lower in the direction of gravity thanat least one of the second flat tubes that is connected to the onecommunication space, the first direction extends in a ventilationdirection, the first heat exchanging portion is disposed on the windwardside relative to the second heat exchanging portion, and the first flattube connected to one of the plurality of communication spaces isconnected in series with the second flat tube connected to the onecommunication space.
 4. The heat exchanger according to claim 3, whereinthe third header has a first plate provided with a plurality of firstinsertion holes through which the second ends of the first flat tubesare respectively inserted, and a plurality of second insertion holesthrough which the second ends of the second flat tubes are respectivelyinserted, and a second plate provided with the communication spaces. 5.The heat exchanger according to claim 1, wherein the first plate issmaller in thickness than the second plate.
 6. The heat exchangeraccording to claim 1, wherein the second plate is configured as amultilayer body formed of a plurality of plate members.
 7. The heatexchanger according to claim 1, wherein each of the first flat tubes andthe second flat tubes has an upper surface inclined with respect to ahorizontal direction, and each of the communication spaces extends alongthe upper surface.
 8. The heat exchanger according to claim 1, whereineach of the first fins and the second fins has a continuous portiondisposed on one side in the first direction and extending in thedirection of gravity, each of the first fins and the second fins isprovided with a plurality of insertion holes disposed on the other sidein the first direction with respect to the continuous portion, each ofthe first flat tubes or each of the second flat tubes being insertedthrough a corresponding one of the insertion holes, and the first heatexchange portion and the second heat exchange portion are disposed suchthat the first direction extends in a ventilation direction and thecontinuous portion is located upstream from the insertion holes in theventilation direction.
 9. A refrigeration cycle apparatus comprising theheat exchanger according to claim 1 as an evaporator.
 10. The heatexchanger according to claim 2, wherein the first plate is smaller inthickness than the second plate.
 11. The heat exchanger according toclaim 4, wherein the first plate is smaller in thickness than the secondplate.
 12. The heat exchanger according to claim 2, wherein the secondplate is configured as a multilayer body formed of a plurality of platemembers.
 13. The heat exchanger according to claim 4, wherein the secondplate is configured as a multilayer body formed of a plurality of platemembers.
 14. The heat exchanger according to claim 5, wherein the secondplate is configured as a multilayer body formed of a plurality of platemembers.
 15. The heat exchanger according to claim 2, wherein each ofthe first flat tubes and the second flat tubes has an upper surfaceinclined with respect to a horizontal direction, and each of thecommunication spaces extends along the upper surface.
 16. The heatexchanger according to claim 3, wherein each of the first flat tubes andthe second flat tubes has an upper surface inclined with respect to ahorizontal direction, and each of the communication spaces extends alongthe upper surface.
 17. The heat exchanger according to claim 4, whereineach of the first flat tubes and the second flat tubes has an uppersurface inclined with respect to a horizontal direction, and each of thecommunication spaces extends along the upper surface.
 18. The heatexchanger according to claim 5, wherein each of the first flat tubes andthe second flat tubes has an upper surface inclined with respect to ahorizontal direction, and each of the communication spaces extends alongthe upper surface.
 19. The heat exchanger according to claim 6, whereineach of the first flat tubes and the second flat tubes has an uppersurface inclined with respect to a horizontal direction, and each of thecommunication spaces extends along the upper surface.
 20. The heatexchanger according to claim 3, wherein each of the first fins and thesecond fins has a continuous portion disposed on one side in the firstdirection and extending in the direction of gravity, each of the firstfins and the second fins is provided with a plurality of insertion holesdisposed on the other side in the first direction with respect to thecontinuous portion, each of the first flat tubes or each of the secondflat tubes being inserted through a corresponding one of the insertionholes, and the first heat exchange portion and the second heat exchangeportion are disposed such that the first direction extends in aventilation direction and the continuous portion is located upstreamfrom the insertion holes in the ventilation direction.